Creping corrugated papers



Aug. 5, 1947.

w. w. ROWE 2,425,207

CREPING CORRUGATED PAPERS 2 Sheets-Sheet 1 Fild Feb. 19, 1940 INVENTOR. mLL/AM Manes Rows.

ATTORNEYAT.

2 7- w. w. ROWE 2,425,207

CREPING CORRUGATED PAPERS Filed Fgb. 19, 1940 2 Sheets-Sheet 2 INVENTOR. MLL/AM "61224:: fowl.

A'I'I'ORNEY5- continuous manner, together with the creping of No. 2,631,308, dated May 25,1937, and the production of special types of creped papers.

- connection with winch my invention may be GEE? G CORRUGATED PAPERS m-"Wallace Rowe, law Ohio, as-

sr to Cincinnati Industries, Inc, a corpora- 2 Figure 9 is a, partial perspective view of a creping doctor which may be used with the This is a continuation in part of my copending application Serial No. 34,68'l, filed August 5, 1935, allowed November 26, 1937, forfeited, and renewed mechanism of Figure 8.

November 1, 1938, now matured into Patent No. v I shall first describe the corrugating portion of 2,199,680, dated February 20, 1940. my apparatus. In the production of iongitudl- Fundamentally my invention relates to the cornally corrugated sheets, by continuous processes, rugating and creping of papers or other webs, as set forth in the patent of Rowe and Morris and finds its most important, though not exclu- 0. Re. 20, dated January 1939, the Web is sive application, in the formation in webs of coractually taken up gathered transversely t rugations which are parallel to the longitudinal 10 is therefore not possible to contact the web simulaxis or the web and which may be formed in a taneously across its width with gathering elements which interdigitate simultaneously and cornsuch webs while in cog-ruggted diti n, I pletely to produce the desired gathering. If this My invention relates to a novel step or series were done, the W Would i and p AS a of process steps which have importance ina pluconsequence it is the usual practice to begin to m of m fields amgng hi h may b gather the 'web at one point (usually, though not mentioned, but without limitation, the corrugatessarily, in the center of it) and then as the m d greping of w b a a, part of a, bst web moves, progressively form additional lateral tially unitary operation, the creping of previously gatherings until t mate y t e Whole W s gathcorrugated webs, the formation of composite fabered transversely ar y a central longituflcs the gsneral types q; fgrth in my t t, dinal corrugation isformed first and after, this has been formed, another corrugation is formed on each side of it, the additional corrugations 1 the copending 'applicatign 1 have described being formed in pairs until the operation is comand claimed the aspect of corrugating, whereas Plated for any given length of the web. If it is in this case the disclosure and claims are directed assumed thalt cflrlugaitihg is b g done by preprimarily to the production of creping crinkles scnting to the web up n o ide, means providin a corrugated web. ing a corrugated surface, and by presenting to it The fundamental and ancillary objects of my on the other side, means which successively and invention will be set forth hereinafter, or will progressively depress the P p between the lands be entirely clear to the skilled worker in the art ridges of e first mentioned corlllgafing on reading these specifications. For clarity in the disclosure, which is to follow, reference is now there a fumes tending to cause p i u y made to the drawings, whereinformed corrugations to come out or be lost during Figure l is a semi-diagrammatic perspective the progress of the web. One of these forces is view 3f one form of eorrugating mechanism in the natural resilience of the web which cames it to tend to become flattened out after it has been cantmd an corrugated. Another of these forces is the actual Figure 2 is a sectional viewor a portion of one pull on a previously formed corrugation caused type or corrugating surface showing one method 40 by the depressing of laterally disposed portions of binding the web to that surface. of the web to form additional corrugations. As

Figure 3 is a sectional view of another type of a consequence, it-has been found in actual pracoq atl g urface, tice, as set forth in the application referred to Figure i 15 a, sectional view of an exemplary above, that, given corrugating means upon one fabric of composite nature. side of the web and depressing means on the other Figure 5 isa perspective view of a special type which act successively to form corrugations by of creped article. inter-digitation, some means must also be pro- Figure 6 is a semi-diagrammatic elevation of vided for holding previously formed corrugations means for corrugating and thereafter creping a as such, at least until the formation of laterally e W l p in t co ugat o s the einadjacent ones. This presents a substantial me- Figure 7 is a partial perspective view of a creping doctor which may be used with the mechanism of Figure 6. 7 Morris, to which reference has been made Figure 8 is a similar view oi mechanism for a Essentially in the practice of my invention I like purpose employing a diflerent doctor. accomplish this purpose by binding the paper to chanical problem, which problem has been solved mechanically by the teachings of said Rowe and ll a means, it will be found in actual practice that a corrugating means, at least at the time of the formation of any given corrugation in a way which will be positive.

As an' exemplary machine .and procedure, I have illustrated in Figure 1, a cylinder l, which is grooved on its peripheral surface. A suitable web 2 is led to the surface of this cylinder in any suitable way, and in order to form corrugations therein, the paper is successively depressed into the grooves of the cylinder by a series of progressively acting elements starting with a center roller or sheave 3, followed by laterally adjacent ones 4 and 5, and additional pairs of laterally awacent ones 6 and 1, etc. This arrangement alone would not be commercially successful for the manufacture of corrugated paper without the provision of holding means as aforesaid. This holding means I provide by adhesively binding the paper to the cylinder as the corrugations are formed therein, the adhesive beingsufllcient to maintain the corrugations while others are being slippery enough to permit side slip of the web during corrugating, but which, once the web has been pressed down into a groove will quite strongly resist the direct lifting action encountered when adjacent corrugations are being produced. Again the adhesive may be used in various ways, e. g., applied to the bases of the grooves only of the grooved member, or applied to the tops of the lands or ridges only, or applied all over either the web or the grooved member, or both.

I have shown in Figure 3 an exemplary form of corrugated surface useful where fairly large amounts of lateral stretch are required. Here the cylinder is grooved as at 8 and between these grooves there are relatively narrow, but relatively highlands or ridges 9. A. paper web I is shown in a somewhat exaggerated form following the corrugations of the cylindrical surface. I have indicated this paper as being bound to the cylindrical surface by an adhesive substance H. I have shown this adhesive substance as lying in the bases of the grooves so as to cement the paper to the cylinder only at this point. This has a number of advantages, one of which (because it has to do with the corrugating of the paper) may be mentioned 'at this point. It is convenient in this operation to apply the adhesive substance to the cylinder rather thanto the paper, and to locate it in lines in the base of the grooves. This may be accomplished by coating the groove base with the adhesive prior to leading the paper to the cylinder, as by means of small coating rollers which enter the grooves and which turn in a pan of adhesive, or otherwise have adhesive applied to their peripheral surfaces. The paper, being free of adhesive, and the portions of the cylinder surface which contact the paper prior to the formation of corrugations therein bein also free of adhesive, no resistance is interposed to the sidewise gathering of the paper through the action of the inter-digitating means 3, I, 5, etc. Nevertheless as soon as any portion of the paper has.-

been depressed into the grooves, such portion of the paper is firmly bound thereto in a way which will maintain its corrugated form.

It is not outside the scope of my invention, however, to coat either the entire surface of the cylinder or the entire surface of the paper or both with adhesive, prior to the corrugating of the paper. It is also possible to employ an adhesive substance which is normally non-adhesive or which has been caused to assume a non-adhesive state, and then to develop adhesiveness therein as and when desired, viz., upon the corrugating of the paper. Asphalt or other bituminous substances though not the only adhesives which I may employ, are highly advantageous for certain types of work. Bitumens may be chosen which are substantially non-adhesive at ordinary temperatures, but which may be caused to become adhesive upon the application of heat; and heat may be applied either by external means, by

controlling the temperature of the corrugating member i, or by heating the depressing means I, 4, 5, etc. This is also true of other thermoplastic I substances, including but without limitation, in-

equivalent device just ahead of the creping line,

or line of engagement of the doctor with the web.

My process and mechanism is adaptable to the corrugating of papers which have not previously been creped, as has been seen. If plain paper is being operated upon, it may be creped transversely at the time of the removal of such paper from the corrugating means. I am aware that it has hitherto been suggested to lead paper on to a corrugated cylinder and remove it therefrom by a serrated knife so as simultaneous y to crepe and wave the paper. This however, has not proved to be practicable, and so far as I know there has hitherto been no commercially successful operation of thi kind. While it is true that no successful way has been found to bind the paper to the corrugated cylinder, and that moisture alone cannot be depended upon, while the use of vacuum or air blasts has likewise not been a success, and while a positive adhesive union of the paper and the corrugated cylinder or the like solves this aspect of the diiliculty, yet the failure of the prior art to crepe successfully from a grooved cylinder has inmy opinionbeen due to a lack of understanding of the principles which I shall now set forth.

Consider'the situation shown in Figure 2-a corrugated cylinder la, with a paper web in cemented solidly to the surface thereof. over its entire area, by the cementing medium Ila, which may in this case be an asphalt or the like, but may also comprise a number of other adhesives,

such as latex, rubber-resin combinations, incom-m pletely polymerized synthetic resins, etc. It is possible merely to scrape the web from the cylinder with a sharp knife-that is to say a knife or doctor contacting the cylinder and having so large a meeting angle of its surface with the surface of the cylinder as to exert only a liftingaction upon the web. This is feasible if the knife is so disposed as not to-tear the web by lifting parts of the web from the ridges or lands of the knife or docter which has a, meeting angle of its surface with the surface of the cylinder so small as to crowd the paper back upon itselfto form creping crinkles in it-that is to'say, in order to crepe one must employ a doctor which will provide a proper creping angle or creping V. For commercially desirable amounts of longitudinal stretchability a creping l of no larger than 90 is desirable; and the amount of stretchability will be influenced by the creping angle or v.

Another consideration, however, is this: that in creping on a. grooved cylinder the web has already been contracted widthwise by being caused to conformvto the lands and grooves of the cylinder. Being bound to the cylinder, it cannot contract further in the widthwise direction. If the corrugations are to be fully preserved, the crinkles must be imparted to the web in such a way as not to tend to contractthe web further in the widthwise direction. The crinkles thus must be formed straight and truly transversely to the corrugations and to the major axis of the web.' Where it is desired to preserve the corrugations intact, at second desideratum therefore is that the edge of the knife contacting the cylinder as the web approaches the knife, must contact the cylinder at points all of which lie in a radial plane.

This may be accomplished in several ways. In Figure 6, theweb 2 is shown as being caused to conform to the grooved surface of the cylinder l by the elements It, 5, 7, etc., which may be rubber covered to provide better equalization of pressure. A creping doctor or knife I! (the contacting edge of which has been shaped to conform to the surface of the cylinder) is shown so disposed that the leading face ill of the knife lies in the radial plane R. Figure 7 shows in perspective a portion of the knife, indicating how the knife has been shaped to conform to the cylinder as at 20. I shall hereinafter refer to a knife so disposed as a radial knife. For simplicity in this and the. other figures I have not indicated the knife supporting means.

It will be evident that, with a'knife as shown, the creping V is the angle of incidence of the knife face it with the surface of the cylinder. Since the knife is a radial knife this angle of incidence will be 90 at all points. It will not be feasible to tilt the knife very much from the radial plane R. If the knife is tilted forwardly, it will begin to remove the web from the lands before it is removed from the grooves. Under these circumstances the web may rip at the lands if weak,

or lift in the bases of the grooves and fail properly to crepe there. If the knife is tilted backwards, the creping V is made more open on the tops of the lands and bases of the grooves. In either event the crinkles would not lie straight and truly transverse to the corrugations. Of course. with a thick knife configured as at in a certain way, it is not possible to tilt that knife very much and have it still conform to the surface of the cylinder, as will be clear. But by varying the configured surface to it is possible to tilt the knife a very few degrees from the radial plane and still operate successfully depending upon the nature of the web. This is contemplated in invention; still with such a knife it must be disposed substantially in a radial plane.

Where the creping v of substantially 90 is too open to produce the desired longitudinal stretchability, my invention contemplates the machining or grinding of the edge 20a (Fig. 7) to provide a creping v of smaller angularity, while keeping .the meeting points of the knife with the cylinder all substantially in the same radial plane.

There is next the problem of the removal of the creped web from the creping line. The cylinder has a grooved surface, and the creping has been done in such a way as to preserve the corrugations in the web. If the web is removed from the cylinder at. any considerable angle to the cylinder surface, there will be a differential stretching of the web in different parts of the corrugations which will tend to flatten the web. This must be avoided if the lateral stretchability is to be preserved. Thus a third desideratum in creping a corrugated Web where the corrugations are to be maintained intact, is to remove the web after creping, along a line which is tangential to the cylinder surface, or more closel approaches the tangential than a radial direction.

In Figure 6, I have shown the web leaving the knife I? in a, direction substantially opposite to the direction in which it approached the knife, at 2b, over a flight of supporting rolls 2 8. Note that when the web is removed in this way its adhesive coated side is up and away from the rolls 2!. While at first glance such removal of the web might seem to imply a reversal of the corrugations in the web, this is not in fact the case. The ease of bending of the crinkles transverse to their direction facilitates the reversal of the direction of movement of the web; indeed the web is pushed back by the knife in a direction opposite to the direction in which the web approaches the knife. Analysis will show that the portions of the web which werein the grooves as the web approached the knife are still (in the web as it'is removed at 21)) lower than the portions which lay on the landsso that the web has not been turned inside out.

With a knife such as l2 in Figure 6 it is not possible to remove the web in the opposite substantially tangential direction. In Figure 8, I have illustrated the use of a tangential knife 22, shaped on its underside to conform to the cylinder surface at the tangent line, and having a forward edge terminating at the tangent line so that all points in the edge lie substantially in the radial plane R. The angle of this edge to the cylinder surface is the angularity of the creping V. The web may be removed in the reverse direction at 2b (as before). But if the knife is corrugated on its upper surface (as for examplaif the knife is a corrugated knife as shown at 22a in Figure 9), the web may be removed in the opposite substantially tangential direction 20 if desired, While maintaining the original high and low disposition of the ridges and valleys in the web. In the knife 22a the edge surface 23 may be milled or ground to provide a creping v of desired angularity. Since all of the points in the meeting line between the surface of the cylinder and the edge 23 lie substantially in the same radial plane, the knife 22a or 22 is a1so in this sense a radial knife."

When operating with plain papers, it is likewise possible to cement the paper only to the bases of the grooves and/or to the tops of the lands, the first being shown in Figure 3, and the second being a variant thereof. When this is done, the paper is not bound to the corrugating surface over its entire area. In those places where the paper is free the crowding action of the doctor is somewhat relieved and the paper is evenly and finely creped along-those lines where itis positivel adhered to the corrugating means, but is ruilled or more or less imperfectly creped elsewhere, giving a paper of novel appearance.

The use of interspaced lines of positive adhesive suggests the use of this device to make semicreped papers of novel appearance without substantially corrugating them. In this aspect paper may be bound to a plain cylinder or other plain creping surface by means of interspaced lines, areas or dots of positive adhesive and then may be removed therefrom by a doctor, giving a fine creping in the areas of adhesive union, and a ruiiied appearance therebetween. vA sheet creped by means of inter-spaced lines of adhesive is 11- lustrated at if in Figure 5, where H indicates areas of creping and I indicates areas of milling. This can be done either on a plane cylinder or on a grooved cylinder.

The adhesive may, if desired, be printed on the web or on the creping cylinder in interspaced areas by a printing cylinder.

Or the web or cylinder may be solidly coated, and the effect obtained by applying pressure only at interspaced areas. Thus if a solid y oated sheet were pressed against the creping cylinder by means of a rubber covered roll with the rubber cut out in areas like a printing plate, the pressure areas contrast strongly with the non-pressure areas.

In my Patent No. 2,081,308 I have taught, among other things-the making of composite fabrics comprising a base material and a multi-laterally stretchable web secured to said base material only at intervals. such fabrics having a number of novel and useful characteristics.- It will be clear from the foregoing that the process of binding the paper to corrugating means at interspaced intervals, or along interspaced lines, greatly facilitates the formation-of such fabrics. Not only is the adhesive applied as a part of the corrugating operation, so that additional adhesive application may not be required, but where the paper is bound to the corrugating means, at the bases of the grooves, the adhesive will be found properly placed to bind a corrugated sheet to the base material at the crests of the corrugations. Where the tackiness of the adhesive substancehas been relieved at the time of removal of the web from the corrugating surface, it will be redeveloped therein at the time of the union of this web to the base material, by the application of heat, a solvent, moisture or otherwise. Moreover, the corrugated web may be Joined to the base material prior to the crushing of the corrugations therein. If this is done, and the base material and the corrugated web pasted together through My process is applicable to webs in general including but without limitation webs of paper or hacked or unbacked metal foils.

crushing means, the base material of course acts to maintain the corrugations during the crushing and prevents the loss of stretchability.

I have indicated in Figure. 4, a crushed and corrugated web it, joined to a. foundation material such, for example, as burlap H, by being cemented thereto with adhesive l8, positioned essentially at the crests of the corrugations on that side of the corrugated web which falls against the foundation material. In Figure 6, I have indicated a web 3! being brought against the web 2b between pinch rolls 32 and 33 to form a somewhat simiiar product.

Modifications of my invention may be made without departing from the spirit thereof, and I do not desire my invention to be limited otherwise than as stated in the appended claims, wherein I have endeavored to set forth what I believe to be the essential novelty of my invention.

I claim:

1. A process of producing a creped and corrugated web which comprises causing said web to conform to a corrugated creping surface with the interposition of an adhesive between said creping surface and said web, whereby to corrugate said web by taking it up widthwise across said surface, causing said adhesive to bind said web to said corrugated surface and afterward removing said web from said corrugated surface by a creping doctor contacting said surface along a line normal at all points to the corrugations therein.

2. A process of producing creped and corrugated webs, which comprises providing on one side of said web, means presenting a cylindrical corrugated surface, progressively depressing said web between the ridges of said corrugated surface by means acting from the other side thereof, and causing portions at least of said web to come into adhesive union with said means presenting a corrugated surface prior to the formation of adjacent corrugations therein and removing the web from said surface by means of a creping doctor having contact with the said surface at points all of which lie substantially in a single radial plane.

3. A process of corrugating and creping a web which comprises providing a cylindrical corrugated means, coating the bases only of the grooves therein with an adhesive substance, bringing paper into contact with said corrugated means and successively depressing said paper into the grooves thereof, whereby as each corrugation is formed therein it is held by said adhesive at least until the completion of the formation of adjacent corrugations therein, and removing said web from said corrugatingmeans by a doctor, said doctor contacting said cylinder at points all of which lie substantially in a single radial plane, and removing said web in a reverse, substantially tangential direction.

4. Apparatus for producing a creped and corrugated web which comprises means presenting a corrugated creping surface to which a web may be made to conform with the interposition of an adhesive between said creping surface and said web, means to cause said web to conform to said corrugated creping surface whereby to corrugate said web by taking it up widthwise across said surface and whereby to cause said adhesive to bind said web to said corrugated surface, and a creping doctor for removing said web from said corrugated surface, said creping doctor contacting said surface along a line normal at all points to the corrugations therein.

5. Apparatus as claimed in claim i wherein said means presenting a corrugated creping surface is a corrugated creping cylinder and wherein said creping doctor is disposed radially of said cylinder and has a lateral face forming with the surfac of said cylinder a creping V, said lateral face lying in a radial plane. 1

6. Apparatus as claimed in claim 4 wherein said means presenting a corrugated creping sur 4 face is a corrugated creping cylinder and wherein said creping doctor is a member lying tangen tie-11y to said cylinder and shaped to conform to the surface thereof, said doctor having a planar edge portion at said cylinder, said edge portion lying in a radial plane of said cylinder,

REFERENCES CITED The following references are of record in the file of this patent:

I Number Number Name Date Wandel May 31, 1927 Christman Jan. 28, 1941 Rosenfeld et a1. July 11, 1939 Cohoe 0ct. 10, 1939 Angier Nov. 24, 1936 Lorenz Aug, 4, 1925 Goodlett May 10, 1927 Lorenz Aug. 18, 1925 Wendel May 31, 1927 Angler -1 Nov. 24, 1936 Rowe Feb. 20, 1940 Lorenz Aug. 4, 1925 Lorenz Aug. 18, 1925 Goodlett May 10, 1927 Wandel May 31, 1927 Angier Nov. 24, 1936 Rowe Feb. 20, 1940 FOREIGN PATENTS Country Date Great Britain Aug. 13, 1931 

